1. Field of the Invention
The present invention relates to snap locks in general and, more specifically, to a positive action fenestration lock, i.e. adaptable to be attached to a moving window profile and to interact, by sliding, with a fixed window profile.
2. Description of the Prior Art
The particular class of latches to which the present invention pertains uses latching plates with latching shoulders, between which a land to provide an abutment is formed. The latching shoulders are inclined with respect to a vertical surface of a widow frame. For example, U.S. Pat. No. 5,901,501 dated May 11, 1999 and granted to Fountaine for a “Window Fastener” describes a lock for use with a sliding sash window. The lock has a body with a handle mounted with the body for pivotal movement about a pivot axle. A latch tongue is operatively coupled to the handle and a latch tongue is provided with a latching surface for contacting an end of the latch tongue. The latching surface is spaced from the pivot axle in the direction in which a sash of a window is movable from a closed position elative to the frame of the window. The handle is movable about the pivot axle to move the end of the latch tongue away from its latching contact of the latching surface of the latch plate. Thus, the window sash can be moved from the closed position. Fountain's “Window Fastener” has several important shortcomings. First, the latching tongues are moveable independent of each other and of the handle. Second, there is a limited pivot movement of the tongues by the handle. Third, sliding action is not rectilinear.